Mitosis Inhibits DNA Double-Strand Break Repair to Guard Against Telomere Fusions

Shutting Down Repair to Protect Cells repair DNA double-strand breaks (DSBs) by halting the cell cycle and activating the machinery involved in mending the breaks. However, during mitosis neither the DNA damage checkpoint nor DSB repair occur, apparently leaving the cell extremely vulnerable to DSBs. Orthwein et al. (p. 189 , published online 20 March) found that the DSB response was blocked by the phosphorylation of two crucial repair factors,...